Bioelectrical Impedance Analysis for Evaluation of Donor Hepatic Steatosis in Living-Donor Liver Transplantation

Bioelectrical Impedance Analysis Can Be an Effective Tool for Screening Fatty Liver in Patients with Suspected Liver Disease

Background and study aims: Although abdominal ultrasound (USG) or controlled attenuation parameter (CAP) score of transient elastography (TE) is recommended for the diagnosis of fatty liver, issues regarding cost and accessibility still exist. The aim of this study was to evaluate if bioelectrical impedance analysis (BIA) can be used as a reliable screening tool for fatty liver. Patients and methods: A total of 249 patients who underwent all three tests including TE, BIA, and USG were enrolled. The correlation between fat mass measured by BIA, CAP score of TE, and fatty liver grade measured by USG was analyzed. In addition, the cut-off value of BIA which can predict the fatty liver grade was calculated. Results: Fat mass index (FMI) assessed by BIA increased significantly along with the rise in fatty liver grade measured by USG (normal: 6.2 ± 2.4, Gr I: 8.0 ± 3.7, Gr II: 10.6 ± 3.5, Gr III: 10.7 ± 3.7 kg/m2, p < 0.001). In addition, a positive correlation was found between the CAP score of TE and the FMI of BIA. Additionally, a total body fat mass increase by 24.3% or 29.8% in men and 34.8% or 35.1% in women increased the possibility of developing any grade of fatty liver or significant fatty liver (≥Gr II fatty liver), respectively. Conclusion: The total fat or fat mass index of BIA was related to fatty liver as assessed by ultrasound or CAP score, and area under the receiver operating characteristic (AUROC) was about 0.8. Thus, BIA can be used as a screening tool for fatty liver in patients with suspected liver disease.

The common PNPLA3 variant p.I148M is associated with liver fat contents as quantified by controlled attenuation parameter (CAP)

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming the most prevalent liver disorder. The PNPLA3 (adiponutrin) variant p.I148M has been identified as common genetic modifier of NAFLD. Our aim was to assess the relationships between genetic risk and non-invasively measured liver fat content.

METHODS

Hepatic steatosis was quantified by transient elastography, using the controlled attenuation parameter (CAP) in 174 patients with chronic liver diseases (50% women, age 18-77 years). In addition, a cohort of 174 gender-matched healthy controls (50% women, age 32-77 years) was recruited. The PNPLA3 mutation as well as the novel NAFLD-predisposing genetic variant (TM6SF2 p.E167K) were genotyped with allele-specific probes.

RESULTS

The PNPLA3 genotype correlated significantly (P = 0.001) with hepatic CAP measurements. The p.148M risk allele increased the odds of developing liver steatosis (OR = 2.39, P = 0.023). In multivariate models, BMI and PNPLA3 mutation were both independently associated with CAP values (P < 0.001 and P = 0.007, respectively). Carriers of the TM6SF2 risk allele presented with increased aminotransferase activities (ALT: P = 0.007, AST: P = 0.004), but the presence of this variant did not affect CAP values.

CONCLUSIONS

The PNPLA3 p.I148M variant represents the most important prosteatotic genetic risk factor. NAFLD carriers of this variant should be followed up carefully, with elastography and CAP being ideally suited for this purpose.